Scientists from The Open University (OU) have discovered a series of large fan-shaped sediment deposits on the surface of Mars. These suggest that Mars once had large seas on its surface and a water cycle similar to Earth. The research also shows when Mars’ climate went from being hospitable to the cold desert it is today.
Published in Earth and Planetary Science Letters, the team of scientists from the OU in collaboration with Imperial College London, the Natural History Museum, and other partners*, measured the detailed geomorphology of sediment deposits at the mouth of Hypanis Valles, a river system on ancient Mars. They discovered that these sediment deposits are the remnants of a fluvial delta – formed where rivers meet the sea.
What is particularly interesting is that there is evidence of multiple deltas up to 140 km from the mouth of the ancient river. This not only suggests that there was a sea on the surface of ancient Mars, but shows a dramatic sea level fall of more than 500 metres. A possible explanation for this is a change in ancient climate leading to the sea starting to dry up approximately 3.6 billion years ago.
Lead author from The Open University, Dr Peter Fawdon, said:
“The research has significantly contributed to our understanding of the climate on early Mars, which we now know went from having a water cycle similar to that of Earth to being a cold, desert-like landscape in a relatively short period.
“We would like to gain a better understanding of how many of these fluvial deltas exist on Mars so that we can determine the position and size of its ancient seas.”
*The research was completed by academics from The Open University in collaboration with: Imperial College London; the Natural History Museum; the Integrated Science Center, State University of New York; Arizona State University; the European Space Research and Technology Centre, Netherlands
Find out more
Planetary and space sciences at The Open University
Study science with The Open University
Research into space at The Open University
Read more OU News articles about Mars